README.md

Observer pattern in Symfony forms

The purpose of this project is to demonstrate the use of the form events. Read a [detailed description] in my blog.

This application allows you to manage locations. LocationController is used to:

• list locations,
• create location,
• edit location.

For simplicity, there is a bare minimum of information in each entity:

• Location contains only a city,
• City contains its name and a reference to the region in which it is located,
• Region has a name and belongs to a country,
• Country is described by its name.

The key element of application is LocationType form type that is used for both creating and editing a location. This form provides the following fields:

• country is a list of all countries
• region is a list of all regions of the selected country. If the country is not selected this list should be empty.
• city - a list of all cities of the selected region. If the region is not selected this list should be empty.

When a country is selected, the list of regions is updated by JavaScript code to contain only the regions of a chosen country. For example if Germany is selected the region list must contain only Baden-Württemberg, Bavaria and other german regions. The same happens when a region changes: the list of cities is updated to contain only the cities of chosen region.

Install

composer install
bin/console doctrine:database:create
bin/console doctrine:schema:update --force
bin/console doctrine:fixtures:load -n

Run in docker

cd docker
docker-compose up -d